Drill



(No Model.)

B. M. BROWN.

DRILL.

Patented Nov. 19, 1889.

MF-villi all" EdwanZJZBrown Wit names N FETEKS Flwibulhngnphur,Washinglon. D- C.

- UNITED STATES PATENT OFFICE.

MORGAN,

KELLY & 00., OF OSAGE, lOlVA.

DRILL.

SPECIFICATION forming part of Letters Patent No. 415,610, datedNovember. 19, 1889. Application filed August 13, 1889. Serial No.320,606. (No model.)

To all whom, it may concern:

Be it known that I, EDWARD M. BROWN, a citizen of the United States ofAmerica, residing at Nashua, in the county of Chickasaw and State ofIowa, have invented certain new and useful Improvements in Drills; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to letters of reference markedthereon, which form a part of this specification.

My invention has reference to expansion- I 5 drills and it consists inthe improvements hereinafter described and set forth, whereby a simple,durable, and eliicient drill is provided that will readily enable tubeor case drilling operations to be conveniently carried on.

In the accompanying drawings,forming part of this specification, Figure1 is a sectional view showing my improved drill within a tube or casing.Fig. 2 is a like view of said drill operating beyond the same. Fig. 3 isa detail perspective view of one of the lower cutters of my improveddrill.

The main drill portion A is of somewhat similar form to the well-knownconstructions and has the drill-edge a located at its lower end, as willbe well understood. Said portion is provided with a vertical recess 1),extending through from side to side. 1 ,Within recess 1), at each side,is located an auxiliary bit-section B, which consists of an extendedrectangular shank (Z, lying in said recess and pivotally retainedtherein by means of a bolt 6,

which passes transversely through the portion A, forming the walls ofsaid recess, and through an opening in said shank, the said 40 openingbeing of slightly-1arger diameter than said bolt, for a purpose to behereinafter explained. At the lower end and at the outer side saidsection B carries integrally a cutting portion f, the inner face ofwhich is curved to have the portion taper to its cutting-edge, and alsoenablejt, when the section B is compressed within its recess, to bear ina correspondingly-shaped recess g, formed in both of the adjacent walls,the width of the portion f being greater than that of its shank, so thatit does not enter the shank-recess.

A bent leaf-spring Q has one end secured to the inner vertical edgeface, so that its bent free portion 7L will bear against a pin 0,intersecting the lower portion of recess 5, and 5 5 thereby serving tonormally throw the lower operating portion of each auxiliary section tothe position represented in Fig. 2.

In practice the improved drill is passed down through the tube orcasing, and while therein will be compressed, as represented in Fig. 1.N ow, when the drill passes beyond the end of said tube or casing thepressure on the auxiliary sections is removed, and their springs throwthem to the position shown in Fig. 2, in which the entire drill can beoperated to bore a hole that will be of such diameter as to enable thetube or casing to readily follow. By having thebolt-hole in the shank ofslightly-larger diameter than that of the bolt the shank can have alimited vertical movement in its recess, so that its end can bearagainst the upper wall of said recess, and thereby relieve the bolt ofthe strain incurred in drilling-an exceedinglyimportant advantage,especially in piercing hard material.

The pressure of the curved inner face of the lower working portion ofeach auxiliary bit and the corresponding recess in the adjacent wallsavoids the clogging and obstruction by clay or dirt, since, as will benoticed, all the vertical faces are inclined or deflected, so that nodirt or clay can lodge thereon.

From the foregoing it will be apparent that my improved drill embodiesmany important 8 5 advantages over previous constructions, and isdecidedly useful and valuable.

I claim- The combination, with the enlarged main drill portion, having arecess, as described, lower cutting-edge and cut-away side wallsadjacent thereto, of independent bolts intersecting said recess,auxiliary drill-sections pivoted upon said bolts by having largeropenings for the passage of the same and provided 5 with the exteriorenlarged cutting portions central stop below said bolts, substantiallyas set forth.

In testimony whereof I affix my signature in presence of two Witnesses.

EDWARD M. BROWN. VVit-nesses:

J. \V. HOWE, HERVEY CECIL WILBUR.

